Vehicle brake equalizer



Feb. 7,111939. J. R. RIPPE v VEHICLE BRAKE EQUALIZER Filed March 11,1955 4 sheets-sheet 1 ,if i/v/f/ 0W i A I @NNN GNN.

INVNTOR.

, JOHN E. IQIPPf mm, @win/,m9 f oc( ATTORNEYS.

Feb. 7, 1939. .1. R. RIPPE VEHICLE BRAKE EQUALIZER Filed March 11, 1955 4 sheets-sheet 2 wv Nw mw. G

f INVENTOR.

BY JOHN E. lQ/PPE mwuwm d ATTORNEYS.

Feb. 7, 1939.

J. R. RrPPE VEHICLE BRAKE EQUALI ZER YFiled March l11, 1935 4 sheets-sheet s INVENTOR. Y JOHN 1. E/PPE f Y- 1 l,

B )MMM dz ad? ATTORNEYS.

Feb. 7, 1939. .1. R. RIPPE VEHICLE BRAKE EQUALIZER Filed Marrch ll, 1935 4 Sheets-Sheet 4 NNW d Jyf .Bm v..v// n containers;

Patented Feb. 7, 1939 UNITED STATES PATENTv OFFICE 13 Claims.

This invention relatesy to vehicle brakes.

It is an object of the invention to vprovide a brake equalizer which operates automatically upon occurrence of an excess pressure in anyone or more of the brake linkages to transmit through a body of uid, such as oil, a surplus of pressure in equally divided portions to respective fluid controlled means for each of the drums embodied in the system, thus to equalize the braking pressure in all the brake linkages and insure a positive and uniform application of the brakes.

fAn important feature of the invention is directed to the use, in a uid controlled pressure equalizing system, of fluid containers which are devoid of valves, and which are designed and constructed to prevent leakage of fluid in the ordinary use of the invention. v

A further object is to provide a fluid equalizer, in which means are employed to insure an operative application of the brakes even though all fluid in the fluid pressure chambers should be lost from the system or in the event'of breakage or accidental disconnection occurring in the linkages.

A still further object is to provide novel positive acting means for rendering the pressure responsive mechanisms active upon the customary 'actuation ofthe brake pedal of an automotive Vehicle. Y

With the above and other objects in view, the invention consists in the novel construction and combination of parts vhereinafter described, illustrated in the accompanying drawings and set forth in the claims hereto appended, it being vunderstood that various changes in the form, proportion, size and rminor details of construction within the scope ofthe claims may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

Referring to the drawings: Figure 1 is a view in top plan of an automobile chassis equipped with conventional brakes,l and showing `an application of the invention thereto; Figure 21s a view in side elevation of a portion vof the chassis showing parts of the invention in full lines and parts in dotted lines;

Figure 3 is a transverse section taken on the line 3-3 of Figure 1;

vFigure Llis a horizontal section of the iluid conn tainers and the hanger or` supportingA means therefor; f

Figure is a sectiontaken on the line 5-5 of Figure 4; Q ,i Figure 6 is a View similarto Figure 5, showing a slightly different manner of assembling the fluid Figure 7 is a View similar 'toFigure 1, illustrating a modified form of the invention;

Figure ais a. genion taken. en the linee-eef Figure 7;

(Cl. 18S-2) Figure 9 is a vertical section through the parts shown in Figure 8 Figure 10 is a section taken on the line IIJ-I0 of Figure 8;

Figure 11 is a view similar to Figure 1, showing another form of the invention;

Figure 12 is a view in side elevation of a part of the structure shown in Figure 11, the view being indicated by the line |2|2 of Figure 11;

Figure 13 is a horizontal longitudinal section through one of the fluid container assemblies employed in the form shown in Figure 11;

Figure 14 is a section taken on the line Ill-I4 of Figure 13;

Figure 15 is a side elevation of the complementary sections of the bellows receiver;

Figure r16 is a disassembled perspective view of certain of the parts of the bellows container;

Figure 17 is a perspective view of a portion of one of the side bars of the chassis showing one of the bellows assemblies supported in operative position and rotated on its axis 90 degrees to the position indicated in the other views.

Referring more particularly to the form of the invention shown in Figures 1-6, inclusive, a conventional form of automobile chassis C is employed. The4 chassis is provided with supporting wheels W, having brake mechanism, for example, of a type embodying brake' drums xed on said wheels and coacting brake shoes or other conventional friction means adapted to be actuated by individual reciprocable brake rods 28o, 29e, 30e and 3| c.

Mounted transversely of the chassis C is a rigid support having a guide 22 containing a horizontally reciprocable member or casting 2| in which cylindersf28, 29, 30 and 3| are formed. The cylinders are disposed with their axes parallel and extending longitudinally of the chassis. They can be disposed in one plane or layer, as shown in Fig. 5, or can be arranged in two planes or layers 2|a communicating through ports 2lb, as shown in Fig. 6, but operate similarly in either arrangement. The cylinders are all of the same length, and in the present embodiment are of like internal diameter and are closed at their front ends by a head I-I, formed as an integral part oi' the member 2|. At their rear ends, said cylinders are closed and securely sealed against fluid leakage'by a removable guide head H. Rods 34 pass throughv the head H and have operative connection at their forward ends with respective pistons 33 closely fitting the cylinders 3| and operating against a non-compressible fluid F in the cylinders. Fluid such as oil, glycerine or the like can be employed- The dividing walls between the cylinders are formed with ports 32, whereby constant communication is established between the cylinders to enable iiuid in any of the jacent'cy'linders. Balancing of the pressures in said cylinders almost immediately follows the occurrence of an excessive pressure in any one of the cylinders. The guide 22 is formed with a longitudinal slot 21 passing a removable filling plug 27a, extending into the reciprocable member 2| so that the cylinders can bev supplied with fluid.

J ournaled to oscillate on the chassis C are rockshafts 28a, 29a, 30a and 3m, having equal length crank arms A2 fixed thereto, to which the "rear ends of respective links 28h, 29h, 30band Sib. are pivotally connected, the forward ends of said links having pivotal connection at P with their respective piston rods. Said shafts 28a, 29a, 30a and 3 la are connected with the respective brakes of the supporting wheels W by means of the brake rods 28C, 29o, 3Go and 3io, the inner ends of which Yhave pivotal connectionwith fixed crank arms A 26 (Fig-4) The rear end of the `link is flexibly connected with the Yreci-procable memberlZl bya hinge knuckle The shaft 23"'is provided with the usual form of foot actuated brake pedal l24.

sponding lengthsfandthe crank arms A at the n When the brakepedal 24 is depressed, the shaft 23 is turned in a clockwise -direction (Fig. 2) actuating the connecting link 25. The block 2| containing the cylinders is'moved rearwardly and, through? the vliquid -F 'cntained in the cylinders, causes motion to be-imparted to the pistons in a braking direction under the'influence of a hydraulically uniform' braking pressure. `1 In response to rearward motion-'of the pistons'33, the links 28h, 29b,'3'0band 3lb are actuated to'impart motion in'a clockwise direction to t-he rock shafts 28a, 29a, 30al and3la, thence to'the brake rods 28o, 29o, 36o and '3Ic. The brakes are thus applied with uniform' forceiat all wheels.v The fixed pistonactuatedcrank `arms AZ-atthe inner ends of thesha'fts 28a, 2911,53001. vand'la, areof correouter ends 'of said shafts'are'likewise of corresponding i lengths and vmay y be I equal I or in v`any selectedlength ratioaccording tothe amount fof force to be lap-plied tothe respective-brake drums. The fluid pressures in the respective piston cylinders are equalizeddespite variations in the brakingsystem, because thecylinders' are in' constant communication with eachother through thebylpass 'ports-2lb` and32. Should the:=pressure occurring'fat anyloneof 4the drums be excessive, `Vor-not the same-as lat 'others-of the drums, the f pressure L difference is transmitted to theiiuidf-bythe piston-corresponding to theparticular brake drumf-and fluid isapp'ropriately bypassed frornoney uniti or `cylinder tothe lothers to balance'the pressuresinthe respective -units or cylinders an'dlthusinsure` equalization of braking forcea-tall wheelsA of thevehlcle.

- In` the formof the invention shownf in Figures 1 forcing the innings lar-1r; frictionn engagement with the inner walls of said drum. The disk4a or brake plate of the axle 4I constitutes a pivotal mounting for the cam 45 as is common Vpractice in the art, and, asillustrated, said cam is mounted to move with a crank arm 40h. i

Between they lower ends of the shoes 36 of each of the aforementioned brake drums and formed as an integral part of the fixed disk la of axle of said shoes are fluidactuated metallic bellows 43. Each of said bellows is formed with an in- "ne'r'hea'd 44 seated'in a complementary recess 45 intheadjacent face of said lug and has a port 56 in liquid-tight communication with the lateral branch41 of a port 48 in said lug (FigurellO). Each bellows is alsoformed with an outer head 49, recessed or slightly cupped at 50 to receive the rounded cam-like nose '5| forming the lower endof'the Vcomplementary shoe 36.`

The fluid supply system employed in this form of the invention consists of a fluid holder 52 mounted at a suita'bleplace on the chassis, as

shown inFigure 7,*and provided with a removableY plug or closure 53v to enable it to be supplied withk fluid. Cross pipes 54 and'55are connected with the uid'holder by longitudinal branch pipes 56, and, as shown in Figure 7, the ends of said 'crosspipes 5,4`and 55 connectwith the ports 48 in ,a

through flexible tubing'5l so that constant intercommunication is established between the fluid holder 52 and all of the various bellows 43.

The brake pedalshaft 58is operatively connectedrwith a rockshaft59 by a power transferring rod 60-in a manner similar to that aforementioned, and, as shown, the front wheel brakes have the crankarms 40h' of-their shoe actuating cams 40 pivotally connected to brake rodsl 6I.

The rods 6I; are in turn pivoted to crank arms 52 fixed-to said shaftrSS. In like manner, the brake ofshaft 58 concurrently transfers motion to the n crank arms-40h to turn the cams 40 so that their lobes'40c are effectively advanced against* the faces139' of the shoes 35. The shoes 36 are thus effectively spread'to'- cause the linings 31 to engage the inner walls of the brake drums. In., consequence of this movementof the shoes36, force is imposed upon the pressurey responsive heads 49 of the bellowsv 43; Should more pressure tend to expend 4itself at one drum than the other, the fluid pressure will beinstantly transferred to the bellows 'of all drums and the total pressure uniformly balanced and divided among them With'a resulting uniform even application of said brakes.V TheY principle embodied'in this form of'th'e invention is'the same as that emr,

bodied inthe'rst form., In each form there is theutilization in a uidpressure system of .surplusenergyto eifect' equal'distribution in all directions Yof .equal pressures, as is made possible by constant intercommunication of the bellows 43 inFigures r'to 10, inclusive, ortheconstant interconnnunication*.between the fluid cylinders SI'inFigureslto 5; inclusive. Y

In the form ,ofthe invention shown infFigures Y 11 to '17;"i'rclusive, of the 'accompanying drawrchassis as shown, and provided with a horizontal cylinder 61 in which the complementary relatively reciprocable elements 68 and 69 of a bellows; container are mounted. These elements are similar in construction yand each comprises a head fhaving side arms 1l-1l apertured at their free ends as shown at 12. Ametallic bellows 13 is disposed between the heads 1010 to be slightly compressed thereby during' relative approaching movement of said elements that enclose the bellows. The head 14 of the bellows is provided with a short pipe 15 which extends through a perforation 16 in the head 10 of element 68, and which is coupled at 11 to a flexible tube 18 forming part of a system of piping or iiow lines 19, the later leading to a fluid holder 89 by way of a pipe 8l, in which there is a valve n ikelement68 is va pin 89 to which a sleeve 99 is secured by a key 9|, the sleeve having a branch 92fin which the threaded end 93 of rod 94 is firmly vclamped by nut 95.

'Thebellows assemblies 65 are thus mounted in longitudinally alined pairs at the opposite sides of the chassis and the brake rods 88 of the forwardly disposed ones of said rbellows are connected with the cam controlling levers 95 of the front brake drums. The rods of the rearwardly disposed assemblies connect in like manner with the cam controlling arms 95 of the rear brake drums.l l y Journaled in the chassis C2 is a transverse rock shaft`96 having its ends provided with oppositely extending fixed equal length crank arms 91 having pivotal connection with the respective power transferring rods 94. The shaft 96 has a crank arm 96'which connects through links 99a with the crank arm 99 on the brake pedal shaft |90. v

When the complementary elements 68 and 69 are interiitted as proposed and intended, they `can slide relatively in a longitudinal direction and the arms 1| of one element will be disposed be-v tween the arms 1l of the other element, the plurality of Yarms defining a cylindrical expansible and contractible container for said bellows 13.

The heads 19 of the coacting elements 63 and 69 will be disposed in parallel relation to each other and in flat contact with the respective heads of said bellows, thus insuring even expansion and contraction'of the bellows in response to force rods 94 of the rear bellows assemblies and a rearward bellowscompressing pull on the rods 94 leading' to they 'front assemblies.

the liquid inthe respective bellows, since the re- Braking force isk equally transmitted to the brake drums through spective bellows are in direct communication with each other through the ow lines 19. Should an excess of pressure occur in any one bellows, the surplus of pressure will pass to the other bellows of the set and the braking pressures made equal at each brake drum.

The diameter of each piston, or the diameter of the metallic bellows, will be proportioned to the effective braking pressure to be utilized at the respective drums. Depending upon the braking effect to be obtained in any specific instance, the sizes of the pistons or the sizes of the bellows may be altered to produce a greater or lesser braking action at 'the rear wheels than would be required at the front wheels.

In Figures '7 and 11 the forms of the invenion therein illustrated are each provided with a single rotative shaft having four equal length crank arms, whereas in the form shown in Figure l, four rotative shafts are employed, each having iixed thereto a single crank arm.

In the form of the invention shown in Figures l to 6, inclusive, the throw of the block or cylinder casting 2l enables the pistons to abut against the head H thereof during movement of the casting in a braking direction in the event that the fluid should be lost from said cylinders, and in like manner abut against the head H' during movement of said castingin a brake releasing direction. Should any one of the brake rods 28o, 29o, 30e or 3io become broken or disconnected from its coacting pressure means, the other pressure means for the remaining drums may still be effectively operated, a feature which is highly important as a safety factor. Assuming that fluid has not been entirely lost from the cylinders and that the linkages between one piston and its brake have been damagedr or disconnected, said piston will be forced back against the head H by the pressure of the liquid against said piston, the uid in the remaining cylinders continuing to function as iirst stated.

' In the form shown in Figures '1 to 10, inclusive, should the metallic bellows 43 become devoid of fluid, they can fully collapse and function as solid stops between the shoe ends 5I and adjacent faces of the lugs 42. The movements of the cams 49 are ample to enable the brakes to be applied even when the bellows are fully collapsed. But, assuming that the fluid in all cylinders is at least partly normal, one of the linkages between shaft 59 and one of the brake drums can be disconnected, and

. fluid pressure will still be effective to apply the disabled brake. Instead of the force being transmitted to the shoes of said brake through the cam 49, the cam merely functions as a stop or bearing between the ends 39 of said shoes and the shoes are actuated directly by expansion of the fluid in the bellows 43 at the opposite ends of said shoes. The oil or liquid in the bellows of the brakes, the linkages of which are intact, will be compressed and thus pressure is set up in the fluid line of the system and utilized to expand the bellows in the disabled brakes. It thus follows that the brake in the wheel of the disabled linkage will be applied against the cam 40, which in this case merely acts as a stop.

The action of the parts shown in Figures 11 to 1'7, inclusive, is substantially like that described in the form shown in Figures 7 to 11, inclusive, in

Athe event of (l) fluid leakage, or (2) a disconnected or damaged power transmitting connection between shaft 96 and a particular brake.

I claim:

l. The combination with a mechanical brake s'y'stemof the ftypeemploylng applurality of rbrake :drum mechanisms "eachihaving'a pair ofexpansible friction devices and means for spreading said devices to vestablish braking contact thereof with the drums; of fluid equalizers interposed between said pair of friction devices and compressible in responseto an excess of braking effect set up in said pair of devices, and said equalizers being in constant communication with eachother so that uponan occurrence of said excess effect sameY -vvill be equally apportioned among all of the equalizers with a resultant balancing of unit pressures therein.

2L The combination with a mechanical brake system of the type employing a` plurality of brake drum mechanisms each having expansible friction devices'and means for actuating said devices to establish braking contact thereof with the drums; of fluidequalizersicoacting with said friction devices :in "response to an excess vof braking effect set up in any onethereof, and said equalizers being in constant communication with each other so that upon" an occurrence of said excess effect samewill be equally apportioned among all of the equalizers with a resulting balancing of unit pres- Vsures therein; the friction devices foreach of the aforementioned drums comprising co-operable shoes, and said equalizers including a fluid bellows interposed between the shoes to be actuated by said `shoes toeifect said balancing of the fluid .n for moving the shoes in a braking direction; a

brake plate mounting, and a-pair of flexible pressure equalizing fluid containers interposed between the shoes to impo-se a load on the fluid in response to the braking effect of the shoes when the shoes have been vmoved in the aforestated braking direction.

4. In a brake equalizer, a brake drum having pressure shoes for frictional engagement with the-walls thereof, brake pedal controlled means for moving the shoes in a braking direction; a brake plate'mounting, and a pair of flexible pressure equalizing fluid containers interposed between-the shoes lto impose a load on the `fluid in responseto'the braking effect of the shoeswhen the shoes have been moved inthe aforestated brakingdirectionyand means establishing communication between the containers and an external fluid flow line.

7'5. In a brake equalizer, a brake drum having pressure shoes for frictional engagement with the walls thereof, .brake pedal controlled means nal fluid flow line and comprising means on the brake plate having ports opening to said containers.

` 6. In a vehicle brake mechanism, a dr'um having-'pressure exerting means movable from a released position to a position to impose braking pressure' on the drum; a disc having fixed ported means extending into the -drum;'a fluid bellows interposed between saidpressure-exerting means amants -a'nd'the ported means and` communicating with K the port thereof and saidbellows'beingsensitiveto `circumferential and radial loads imposedfthereupon by the pressure exerting means, whereby to transmit the force of the loads'to the fluid'insad bellows.

r'7. A vehicle brake comprisinga'brake drum', a f

pair of brake shoes within said drumgapairof expanding means disposed each 'betweenad'jacent ends of said brake shoes and forming' the ing means for hydraulically resisting the opera#- y tion of said one of saidexpanding means. Y

8. A vehiclebrake comprising a brake drum,'a

substantially rigid brake shoe within said drum,

means at one end of said brake shoe for forcing said shoe against said drum, means at the other end of said brake` shoe Yfor forcing said shoe against said drum, said forcing meansbein-gwth'e sole means for restraining rotation of said shoe with said drum, means'for mechanically operati# ing one of said forcing means, means included in the other forcing means for hydraulicallyres'is'ting the operation of said one of said forcing means, and spring means for urging said brake shoe bodily against both of said forcing means,

9. A vehicle brake comprising a brake drum',;a rigid, approximately ,semi-circular' brake `shoe within said drum, a hydraulically lsupported.v

yieldable chamber abutting one end of said brake shoe, a mechanically operable cam vabuttingthe other end of said brake shoe, and yielding means fo-r urging saidbrake shoeto be supported Yagainst rotation solely by said chamber and said cam.

10. A vehicle brake comprising abrake drum,

a pair of rigid, approximately semi-circular brake shoes Within said drum and free to move lil() bodily therewith, a hydraulically supported yieldbrakey shoes for preventing circumferentialrotation of said shoes but permitting substantial bodilymovement of each of said shoes radially toward said yieldable chamber. Y;

11. A brake mechanism comprising a drumfa substantially rigid arcuate shoe vmovable vinto frictional engagement with theinternal surface thereof, a circumferentially and radially lyieldable hydraulically supported chamber abutting one end of said shoe, 'and means acting against the opposite end of `said shoe for carrying thevr same into frictional engagement with said drum. 12g-A brake mechanism comprising 4a drum, movable brakev actuatingl and equalizing members within said drum, and an arcuate brake shoe supported against rotation within said drum solely by having its ends urged into free contact with said members.

13. A brake mechanism comprisingYV a drum, va

Apair of Amovable-abutments within said drum,

and an arcuate brake shoe supported against rotation solely by havingits ends urged Vinto free contact with said abutments respectively and movable by either or both thereof Vinto-frictional engagement with saiddrum. Y

JOHN R. RIPPE. i 

